I have a scene in my story where the main character (the story is told from his POV) opens a door and there is a monster in the room.
I want a sudden introduction, to show how shocked the character is, but I also want to give a description of the monster, or at least give an idea of what it looks like.
How can I achieve both in the same paragraph?
The character was not expecting the monster, because monsters should not exist in his world.